Furnace.



No. 888,057. PATENTED MAR. 24, 1908.

M. VAN B. SMITH.

FURNACE.

APPLICATION FILED NOV. 30. 1906.

2 SKEETS-SHBET 2.

WIWESSES: INVENTOR 1 ATT' RNEYS erenee being bad to the accompanying draw MARTIN VAN BUREN SMITH, OF NEW YORK, N. Y.

summon.

Specification of Letters Patent.

Patented March 24, 1908.

Application filed November 30, 1906. Serial No. 345,584.

T all whom it may concern:

Be. it known that I, MARTIN VAN BUREN SMITH, a citizen of the United States of America, and a resident of New York city,

county, and State, have invented certain: new and useful Improvements in Furnaces, F

of which the following is a specification, refings, forming a part thereof.

My invention relates to improvements'i furnaces, and particularly to improvements in puddling furnaces.

The main object of my invention is to provide a furnace in which both the temperature and the'quality of the flame in the puddling chamber may be varied and determined at will, and wherein a comparatively low degree of heat may be generated in the chamber in which the fuel is burned, which chamber is usually termed the furnace or combustion chamber.

To these ends I provide a furnace of such a type as will first generate gases at a low temperature with a minimum of air, second, I provide for admission of sullic'ient air only to the fuel to support initial combustion in the furnace chamber, while at the same time supplying air in relatively large quantities over the top of the fuel, and the combustible gases evolved therefrom, so that the gases and air will pass together, but in a substantially unmixed state, into the puddling chamber, and third, I so baffle the air and gas at the end of the uddling chamber as to cause the same to mix and to be deflected directly upon the material therein which is being treated.

My inventlon also consists in many novel features and combinations of arts as will be hereinafter more fully set orth, and, in order that m invention may be thoroughly understood, will now proceed to describe a furnace embodying my. invention, having reference to the accom anying drawings illustrating same, and wilFthen point out the novel features in claims. Inthe drawin s Figure 1 is a view in central longitudina vertical section through-a furnace constitutingan embodiment of the invention. Fig. 2 is a view in horizontal section therethrough. Fig.3 is a detail view in vertical transverse section thereof, the plane of section being taken subsfantially upon the line 3-3 of Fig. 2. Fig. is a debustion chamber 5 and apuddling chamber 6, the two said chambers inclosed in a structure of the general type known as reverberatory furnace. The combustion chamber and puddling chamber are divided by means of the usual bridge wall 7, and an-arched dome 8 forms a roof for both, which roof acts to deflect the gases in a manner well understood.

The hearth, or fire grate, in the furnace chamber, comprises a number of plates or bars 9 supported upon cross bars 10, and arranged so close to each other as to form a practically continuous support. In other words, tlus support is arranged to prevent the passage of air therethrough, instead of to permit it, as is usually the case in the gratevbars which are ordinarily em. loyed. Adjacent this hearth, and between t 1e ends of the bars 9 constituting same and the side of the bridge walls 7, is a fuel feeding means, here shown as an under-feed stoker. This stoker comprises a feeding chamber 11, in which is arranged a feed screw 12 and a wind box 13 to which air is admittedthrough a supply pi e 14.

I he wind box communicates with the interior of the feed chamber llthrough side twyers 15, which admit a certain quantity of air to the fuel, as it is fed in, for the purposes of promoting combustion. The wind ex 13 is, however, provided; with large 0, enings 16 in the side thereof which is furt est away from the bridge wall 7 such openings being controlled by doors 17. These openings communicate directly with the space beneath the hearth, so that air, entering the wind box of the stoker, will pass freely through the said openings into the said space. The forward ends of the bars 9 are so arranged as to permit free passage of the air thus introduced past same, which air will then ass around to the top of the fuel, there to sti 1 further promote combustion. When considerable air is thus introduced, however, the larger quantity will ass u ward to the top of the furnace beneatllthe ome 8 thereof, about as shown by the arrows in Fig. '1 of the drawings. This airwill continue along beneath the said dome 8 until it reaches the .end of the chamber 6 At the end of this chamber there is a dead wall- 18, which will tend to deflect the air back again and cause the same to mingle with the combustible gases in the puddling chamber. An opening 19 is arranged comparatively well down in the said end wall 18, which will carry away the spent gases, but this opening it is of comparatively small cap acity-is still further choked by being continued in the form of a plurality of vertical downwardlygrojecting passages 20 (see Figs. 1 and 2), sal passages finally leading to a flue 21, which, in turn, carries the said. spent gases to a main flue 22 with which a number of furnaces may con-.

nect, and which finally terminates in the base of the main stack or chimney,

It will be noted that, whi e the ortion of the furnace above described, whic includes the combustion and puddling chambers up to the dead wall 18, is of the reverberatory type of furnace; the portion in continuation thereof including the assages being substantially of thetype of the Siemens regenerative furnace. At this part of the furnace the gases are prevented from passing away until they have given up almost all of their heat, and, in order to still further baffle the same, I have provided a damper 23 in the flue 21, which may be closed to a greater or less degree as'may be desired. In order to prevent the possibility of burning the damper, and also in order to provide sufficient oxygen to burn up any carbon which may have come over into the flue in the form of soot, I have fitted the damper loosely in the dome of the flue 21, so that air may be freely admitted in the space 24 behind same.

' In operating a puddling furnace; it is well understood that the quality of the metal produced varies greatly in accordance with the treatment it has received, and greater variations are produced by differences in the temperature and quality of the flame employed than by anything else. At certain times a high temperature with a highly oxidizing flame isrequired, while, at other times, a high temperature with a non-oxidizing flame is necessary. Again, at other times a ,ower temperature is wanted. In general a high degree of heat and an excess of air for oxidization purposes is required when first melting the pig iron, scrap, etc., because, during this operation, the silicon etc. is required to be oxidized. After the charge .is thus melted the temperature should be reduced, and the amount of air admitted greatly diminished. At this time oxid of iron, often in the form of scale, and commonl called fix is mixed with the molten 'metafl oxid of iron will at this time give up its oxygen, which, uniting with the carbon and remaining silicon of the pig iron, hastens its purification. This action causes the ebullition which is commonly called fboiling. After thematerial has thus come to a boil,

\ always admitted for such purpose.

the temperature of the flame is required to be raised so as to keep the puddlingchamber at a high degree of heat, but at such time a nonoxidizing flame is required, and not an oxidizing flame, as during the first part of the o eration. Finally, under the influence of t is heat and of the stirring, raking, separating and spreading about of the whole mass in the furnace, the rabble, which is what the mixture is called up to this point, is finally flourished or brought to nature. When the iron is sufficiently in nature it is collected together in lumpsor loops, and, during this time, the temperature may be more moderate, until, finally, the lum s or loops l which are now substantially in t e form of balls, may be drawn from the furnace.

It has been a matter of the greatest difficulty in the past to properly regulate the temperature and quality of .the flame, be-

cause, while it was possible to increase or decrease the temperature of the flame by increasing or decreasing the amount of oxygen supplied, it was amatter of great difficulty, and, in fact, almost an impossibility, to properly regulate the oxidizing or non-oxidizlng quality of the flame when sufficient ail was supplied thereto to give a high teu1- erature. In the present form of furnace, however, if excess of air is supplied tothe furnace, the said air will be caused to take such a path (illustrated in the drawings by the arrows) as will make the air readily available, not only for increasing the temperature of the flame, but also for producing an oxidizing, effect upon the material. In other words, an excess of air, instead of producing an oxidizing flame and a. tremendous heat in the furnace chamber, will rise and pass along the roof of the furnace in a substantiall separate strata, but along with the gas, until finally, mixture of the same will take lace in. the puddling chamber instead of in the cor bustion chamber; and the excess'of air 11 1'. so combined with the products of combustion will be in the proper location to beimmediately effective in oxidizing the material as required.

The quality of flame generated in the com side by side, will prevent air from being drawn upl through the burning fuel, as is usual,- e major quantity of the air being thus free to be delivered for mixture with the products of combustion in the puddling chamber instead of in the chamber 5, or for combining with the material being treated. I consider this to be broadl new, as, so far as I am atpresent informe com letecombustion usually takes place in t e furnace chamber, a sufficient quantity of air being For this reason I 'do not wishto be confined to any have also provided a suitable opening 27 in may be necessary, peri'uitting also the ready air to be heated to the combustion chamber,

particular form or arrangement of furnace, 4. In a furnace, the combination with a or of means for admitting fuel or air thereto. chamber contammg-a hearth for rece vmg In the specific form of under-feed stoker. theluel for combustion, and aworkchamber which I have illustrated, l have merely intended to show one means by which fuel l may be conveniently fed into. the chamber 5. l At the sa'ine tinie the form. of the stolcer is i such as to form a ready and convenient means for admitting air'for use both in the: combustion chamber and in the puddling: chamber. 1

Beneath the furnace chamber I have pro- 1 vided an ash pit 25 with a water seal 26 to revent air from blowing out therethrough;

front of the ends of the bars 9, said opening being normally closed by doors 28. This opening will give the attendants free access to the bars, to the fire, and to the-interior of" the furnace chamber for any purpose which removal lengthwise of the barsf9 when. desired.

What I claim is:

1. In a puddling furnace, the combination with a combustion chamber and means for evolving gases at a low temperature therein, of a puddling chamber adapted to receive gases thus evolved from the combustion chamber, means for supplying highly heated air from the combustion chamber to the puddling chamber in a condition substantially unmixed with the gases from the combustion chamber and means within the puddling chamber to cause the'mixture of the gas and air therein. l j

2. In a furnace, the combination withja combustion chamber for containing fuel, of a work chamber in which heat is to be applied, said combustion and work chambers separated by a bridge wall, means for supplying,

air to' be hegted to the combustion chamber,

and for carr ing the heated air and the products of combustion, one over the other, across the bridge wall into the work chamber, and deflecting means at the end of the work chamber opposite the bridge wallfforfdefleeting the air back toward the work and the incoming gases.

3. In a furnace, the combination with a combustion chamber for containing fuel, of 'a work chamber in which heat is to be applied, said combustion and work chambers separated by a bridge wall, means for supplying and forcarrying the heated air and the products of combustion one over-the other, across the bridge wall intothe work chamber, and deflecting means at the end ofthe work chamber opposite the bridge wall, fordefleeting the air back toward the work and the incoming gases, said deflecting means comprising ja' dead wall at the upp )ortion ofthe furnace, and provided with restricted opening for waste gases below same.

in which. heat is to be applied, in communi' cation with said combustion chamber, of means for admitting air beneath and around said hearth and l'ueli-ontained therein, whereportion of the work chamber and toward the incoming gases. I

5. In a puddling furnace the combination with a chamber containing a hearth for receiving the fuel for combustion, and a puddling chamber arranged in L()ll1ll'lllI1lCiI-ti0l1 with said combustion chamber, of means for admitting air beneath and around said hearth and fuel contained therein, whereby said air will be directed towards the upper portion of said'fiirnace chamber and into the puddling chamber at the upper portion thereof.

6. In a puddling furnace, thecombination with a chamber'for containing fuel for combustion purposes, and a puddling chamber separated from said combustion chamber by v a bridge wall, of a hearth in said combustion chamber for supporting said fuel therein, said hearth being substantially closed to assage of air th'erethrough, and said comustion chamber being provided with a passage around the front end of said hearth, and

.means for admitting air beneath said hearth,

whereby said air will pass around the front end of said hearth and up into the upper por- {)ions of said combustion and puddling chamers.

7. In a puddling furnace, the'combination with a combustion chamber, and a puddling chamber, said chambers separated from each other by a bridge wal of means for admitting fuel to said" com ustion' chamber at a point contiguous to said bridge wall, a closed earth for supporting fuel located adjacent to said fuel feeding means, "said chamber being provided with an air passage around the front end of said hearth, and means for admitting air beneath said hearth, whereby the said air will pass around through the said passage to a point in the combustion cham er above the fuel therein;-

8. In a puddling furnace, theicombination with a combustion chamber and a puddling chamber separated by a bridg'e'wall, of a mechanical stoker arranged contiguous to said bridge wall, a hearth arranged adjacent said stoker for supporting fuel delivered therefrom, and means for admitting air to said stoker and to beneath said hearth, said combustion chamber provided with a pass* age around the front 0f said' hearth through which the air delivered beneath said hearth will pass around to a point in said chamber said stoker and also to beneath the said hearth; said chamber arrangtfi with a passage around the front end said hearth through which the said air thus delivered beneath the hearth will pass around to a point above the fuel contained on said hearth.

10. In a puddling furnace, the combination with a combustion chamber and a puddling chamber separated'from each other by a bridge wall, of a stoker arranged immediately contiguous to said bridge wall, said stoker comprising a feed chamber, fuel feeding means therein, a wind box, a closed hearth arranged immediately adjacent said stoker and upon the side thereof opposite to the bridge wall, said chamber provided with a passage around the front end of said hearth from the lower to the upper side thereof, and said wind box provided with an opening into the space beneath said hearth, and means for admitting air to the wind box for supplying the stoker, and also for disch ge through the ing a feed chamberya conveyer screw therein and a wind box, said stoker arranged immediately contiguous to said bridge wall, a hearth arranged immediately adjacent said stoker, said hearth composed of a plurality of bars suitably su ported and arranged close together, so tliat air will be substantially prevented from passing therethrough, said combustion chamber being provided with a assage around the front of said hearth, and with a door op osite said passage through which access to the said hearthmay be had from the exterior of the furnace, the wind box of said stoker being provided with an o ening therefrom to the space beneath sai hearth, and

with twyers opening into the feedcharnber,

and means for admitting air to the'said wind box.

M. VAN BUREN SMITH.

Witnesses.

D. HOWARD HAYWOOD, ROGER H LYoN. 

